Last week, George Mason University hosted a conference promoting the Boycott, Divestment and Sanctions (BDS) movement, an anti-Israel campaign that has recently swelled its ranks by participating in “solidarity work” with sympathetic organizations. But as the BDS campaign has grown, its “big tent” philosophy may have attracted organizations with ties to terrorism.

In May 2016, for example, the Miami-based organization Dream Defenders flew a group of activists that included a Florida lawmaker to Israel and the Palestinian territories. While in the West Bank, participants were led by a tour guide identified with the terrorist group Popular Front for the Liberation of Palestine (PFLP).

Another BDS group in America with connections to the PFLP is “The US Coalition to Boycott Israel,” or the “Coalition for Justice in Palestine.” While apparently not officially registered as a business or as a nonprofit, this organization claims to work with several groups in the BDS space. The Coalition is, according to available information, coordinated by Senan Shaqdeh, a figure described on the PLO’s website as a former PFLP “mountain fighter” in Lebanon.

It is unclear whether Shaqdeh is still active with the PFLP. But he has helped to coordinate a number of BDS and anti-Israel protests in Chicagoand across the country. Curiously, in 2014, he travelled to Ramallah, where he met with Palestinian President Mahmoud Abbas and Prime Minister Rami Hamdallah.

The BDS campaign in the United States broadly identifies as a nonviolent social justice movement. But, its connections to the PFLP, a decidedly violent group, are troubling.

Founded in 1967 as a Marxist-Leninist revolutionary organization by George Habash, the PFLP was known for a series of plane hijackings in the late sixties and seventies. They placed bombs in supermarkets, gunned down civilians, and hired assassins to massacre passengers at Israel’s Lod Airport in 1970. The group was designated in 1997 as a Foreign Terrorist Organization by the State Department, and it remains on the list to this day.

While it is still believed to be the second largest faction within the Palestine Liberation Organization (PLO), the PFLP is no longer as influential as it once was. But the PFLP remains active in the West Bank and the Gaza Strip, not to mention Palestinian refugee camps around the Middle East. And its commitment to violence has not changed.

In 2011, two PFLP members carried out the murder of a family in the West Bank settlement of Itamar (including a 3-month-old infant). They were responsible for a 2014 shooting in West Jerusalem that killed five and wounded eight. Open-source reports indicate that the group has recently seen an uptick in funding from Iran.

The PFLP and BDS nexus is not limited to the United States. The group is increasingly active among BDS groups in Europe.

Khaled position on violence has not changed. She sees BDS as a means to an ends. In a 2015 op-ed, she notes that BDS “sustains our resistance and our revolution,” But she also notes that, “refusing to buy products in a store or cancelling a corporate contract will not liberate Palestine. Nothing but the Palestinian struggle and resistance in all of its forms, from refusing the orders of an occupation soldier to marching in protests to armed struggle, will liberate Palestine.”

The BDS campaign has always been controversial. It is, in essence, an effort to wage economic warfare against Israel. Whatever legitimacy it has garnered comes largely from claims that it eschews violence. But the campaign’s growing ties to the PFLP tell another story, seemingly validating the harshest accusations leveled against it.